Align each column's cell text in a ListView using a GridView?...

Application: MVVM
Technology: Prism, Unity 2.2

How do you control each cell text alignment in each column?  My ListView is bounded to a property in myEntrySummaryViewModel:

public IObservableEntry Entry { get; private set; }

My ListView in View.xaml is bounded like this:

<ListView BorderThickness="0" Width="Auto"
                  ItemsSource="{Binding Path=Entry.Items}" 
                  SelectedItem="{Binding Path=CurrentEntrySummaryItem, Mode=TwoWay}"  AlternationCount="2"
                  IsSynchronizedWithCurrentItem="True" AutomationProperties.AutomationId="PositionSummaryGrid">

...and the .Items comes from public class ObservableEntry : IObservableEntry like this:

public ObservableCollection<EntrySummaryItem> Items { get; private set; }

...and my GridView nested in my ListView is like this:

<GridViewColumn Header="Compressed Size"  
                  DisplayMemberBinding="{Binding Path=CompressedSize}"
                  Width="Auto" ></GridViewColumn>

... I tried this, but it doesn't work:

<GridViewColumn Header="Compressed Size"  
                  DisplayMemberBinding="{Binding Path=CompressedSize}"
                  Width="Auto" ><GridViewColumn.CellTemplate><DataTemplate><TextBlock Width="Auto" TextAlignment="Center" Text="{Binding Path=CompressedSize}" /></DataTemplate></GridViewColumn.CellTemplate></GridViewColumn>

I want to be able to control each text alignment.  Thanks!...

Code is like a box of chocolates!...